The present invention relates to a device for controlling the height of a load or a load carrier behind the cab of a truck.
Normally, after a tractor has been connected to a trailer or a load carrier on a truck has been replaced with another load carrier, the driver has to leave the cab and visually control the total height of the complete vehicle.
For safety and transport economy reasons it would be advantageous if the driver could get exact information about the total height of the complete vehicle without having to step out of the cab.
It is desirable to obtain a device which can present, on a display on the dashboard of the vehicle cab, information about the height of the load or the load carrier behind the cab provided that the height exceeds the level of the cab roof or the level of a air deflector mounted on the roof. The total height of the cab is known and information about the height of a load or load carrier lower than the cab is less important.
According to an aspect of the present invention a device comprises power operated sensor means supported on the outside of the cab and height adjustable between predetermined upper and lower positions, said sensor means being adapted, during vertical scanning movement, to detect the maximum height of the load or load carrier behind the cab and to send signals representing said maximum height to an indicator inside the cab.
Most long haul trucks and trailers nowadays are provided with air deflectors on the cab roof and such air deflectors are often pivotally mounted and manually adjustable to adapt the height of the rear of the air deflector to the maximum height of the load or load carrier in order to improve fuel economy. Manual adjustment of the air deflector is, however, a complicated procedure requiring that the driver climbs up a ladder on the back of the cab to get access to the air deflector.
In a further development of the device according to the invention for a cab, having on the roof an adjustably mounted air deflector, this deflector is provided with power operated adjusting means and the sensor means are supported on a rear portion of the air deflector. When the power operated means are activated to adapt the height of the rear edge of the air deflector to the maximum height of the load or load carrier this height will be detected by the sensor means.
By providing the air deflector with power equipment for adjusting the height, and mounting the height sensor means on the air deflector, simultaneous adjustment of the air deflector and detection of the maximum height will be obtained.